Conventionally, jacks for vehicle maintenance in garages are hydraulic type which provide high output and efficiency. These jacks usually require some expensive high precision hydraulic elements and thus need careful maintenance. Besides, these jacks are bulky and not fit for vehicle-carrying purpose. For those jacks of vehicle-carrying purpose, some are hydraulic types and some are electrical motor driving types. Both comprise complicated and sometimes sophisticated elements and thus expensive.
Furthermore, the operation of a conventional screw type jack requires an operator an operating device to move forward or backward with the forward or backward rotation of the screw. This sometimes resulting in an unstable operation of the jack.